cgsecurity.org

I also tried setting the partition to none instead of the default EFI GPT. after going through a couple of screens I got to this which seemed promising but it won't let select "Write" because I initially set the partition to "none".

Disk /dev/sdc - 2000 GB / 1863 GiB - CHS 243201 255 63
Partition Start End Size in sectors
P FAT32 0 0 41 25 127 14 409600 [EFI System Partition] [EFI]
P FAT32 0 0 47 25 127 20 409600 [EFI System Partition] [EFI]
>P HFS+ 25 127 15 243184 254 22 3906357344
Structure: Ok.
Keys T: change type,
Enter: to continue
HFS+ blocksize=4096 + Backup, 2000 GB / 1862 GiB

--

Disk /dev/sdc - 2000 GB / 1863 GiB - CHS 243201 255 63
Partition Start End Size in sectors
P FAT32 0 0 41 25 127 14 409600 [EFI System Partition] [EFI]
P FAT32 0 0 47 25 127 20 409600 [EFI System Partition] [EFI]
P HFS+ 25 127 15 243184 254 22 3906357344

Write isn't available because the partition table type "None" has been selected.
>[ Quit ]